I\'m trying to create a build script for my current project, which includes an Excel Add-in. The Add-in contains a VBProject with a file modGlobal with a variable version_N
You can modify the code in the xla programmatically from within Excel. You will need a reference to the 'Microsoft Visual Basic for Applications Extensibility..' component.
The examples on Chip Pearson's excellent site should get you started.